Stabilization of animal and vegetable fats and oils



-Patented Dee. s, 1936 A PATENT OFFICE STABILIZATION OF ANIMAL ANDVEGETABLE FATs ANn on.s

Jam s K. Hunt and George H. Latham, Wilmmgton, Del., assignors to E. I.du Pont de Nemours & Company, Wilmington, Del., a corporation ofDelaware No Drawing. Application February 15, 1935,

Serial No. 6,644

20 Claims.

This invention relates to the stabilization of animal and vegetable fatsand oils and particularly unsaturated fatty glycerides.

It is well known that animal and vegetable fats and oils tend to becomerancid and discolor on storage. It is not definitely known just whatcauses this deterioration. It has been suggested that this deteriorationis due to oxidation or to the. action of micro-organisms or tohydrolytic reactions caused by enzymes or due to minute amounts ofimpurities. Such deterioration is highly objectionable and renders thefats and oils unfit for many uses. Many attempts have been made toovercome this deterioration. It has been proposed to add varioussubstances to the fats'and 'oils to inhibit or retard suchdeterioration. Among 'such substances are certain aromatic aminocompounds. These substances have not proved to be entirely satisfactoryfor the reason that the compounds are too expensive, too volatile,discolor the fats and oils, are toxic, or give the fats and oils anobjectionable odor or taste.

An object of our invention is to provide a new class of compounds to beincorporated in animal and vegetable fats and oils which will retard orinhibit deterioration of the fats and ,oils and will not have thedisadvantageous properties of prior compounds employed for this purpose.A furwill be particularly suitable for use in edible fats and oils.Other objects are to provide new compositions of matter and to advancethe art. Still other objects will appear hereinafter.

These objects may be accomplished in accordance with our invention whichcomprises incorporating in animal and vegetable fats and oils smallamounts of sugar amines. By a sugar amine, we mean an amine of areducing sugar containing a carbon chain of at least five carbon atoms.These amines may be employed as the free bases or as the salts ofaliphatic acids, particularly the long chain fatty acids. The free basesmay be represented by the formula wherein R represents a carbon atom ofa sugar nucleus containing a carbon chainof at least ther object is toprovide such compounds which 1 five carbon atoms and each of R1 and R2represents hydrogen or a carbon atom of an organic group. The sugaramines may also be defined as amino alcoholsin which the alcohol radicalis a normal open-chain radical containing at 5 least five carbon atomsand having a hydroxyl group attached to each carbon other than the oneattached to the nitrogen. The sugar amines may be employed as theiraliphatic ethers or esters, that is, the lfydrogens of one or more ofthe OH groups may be replaced by alkyl, hydroxy alkyl or acyl radicals,such as ethyl, hydroxy ethyl or acetyl radicals. However, such ether andester type compounds are generally less effective and hence are lessdesirable.

Some of the simple primary sugar amines are known and the methods ofpreparing them are also known. Some of the simple secondary and tertiaryamines and the methods of preparing them are known. Some of thesecondary and tertiary amines and methods for preparing them aredisclosed in the copending applications of P. L. Salzberg and R. B.Flint, Serial Nos. 635,- 045; 635,046 and 635,047 filed September 27,1932. issued as Patents 2,016,962, 1,994,467 and 2,016,- 963,respectively.

In general, the method of preparing the secondary and tertiary aminescomprises reacting the sugar with a primary or secondary amine andhydrogen at superatmospheric pressures and temperatures in the presenceof hydrogenating catalyst. For example, methyl glucamine may be preparedby placing 80 parts of methyl amine, 100 parts of commercial glucose and80 parts of water into a pressure vessel with 9 parts of a reducednickel catalyst comprising reduced nickel supported on kieselguhr, thereduced nickel comprising of the catalyst. Hydrogen may be thenintroduced to a pressure of 2000 lbs. and the ingredients agitatedvigorously during the heating. Hydrogen absorption begins at 100 C. andis complete in fifteen minutes. The maximum temperature during this timeshould be about 120 C. The product may be separated from the 45 catalystby filtration, and the filtrate evaporated until crystallization occurs.Methyl glucamine may be recrystallized from this residue as a whitesolid melting at 127-128 C. The reaction taking place may be representedas follows:

NHOH:

Under certain conditions sugar amines may be alkylated by reacting withan alkyl halide or an alkyl sulfate at room temperature or slightlyabove room temperature in order to form secondary and tertiary aminessuch as dodecyl glucamine and dodecyl methyl glucamine. How ever, thisprocess is generally less satisfactory for I the preparation of puremonoalkyi sugar amines than the one given above.

Other amines which may be employed for preparing secondary and tertiarysugar amines coming within our invention are monoethyl amine, diethylamine, monopropyl amine, dipropyl amine, monobutyl amine, dibutyl amineand monoand,di-amines of the higher saturated aliphatic type such asdodecyl and octadecyl amine, phenylethyl amine, monoand di-benzylamine-qr other aralkyl amines, and aryl amines such as aniline,toluidine, and naphthylamine and mixed amines such as phenyl ethylamine, methyl benzylamine and the like. Thus R1 and R2 in the formulaemay be methyl, ethyl, isopropyl, butyl amyl, isoamyl, octyl, dodecyl,cetyl, cyclohexyl, .cyclohexanol, phenyl, phenylol, naphthyl, and thelike.

Among the sugars which may be employed to produce amines coming withinour invention are: glucose, fructose, xylose, ribose, lyxose, lactose,arabinose, mannose, rhamnose, galactose. sorbose, sorbinose, gulose, andtalose.

The sugar nucleus may be alkylated by the usual methods of preparingethers such as by treating with an alkyl halide or alkyl sulfate such asethyl chloride or diethyl sulfate to replace the hydrogens of one ormore of the OH groups by the alkyl group. The degree of alkylation willdepend primarily upon the proportions empl y o I The sugar nucleus mayalso be acylated. The method of preparing such compounds comprisestreating the sugar or sugar amine with an acid halide or anhydride suchas acetyl chloride or acetic anhydride under anhydrous conditions and atsuperatmospheric temperatures. The resulting compounds are esters inwhich the hydro gens of one or more of the OH groups are replaced by theacid radical. The degree of acylation will depend primarily upon theproportions tion the preferred modes of carrying the same of theingredients employed.

The hydrogens of one or more of the OH groups of the sugar radical maybe replaced by hydroxy alkyl groups by reacting the sugar or the sugaramine with an alkylene oxide such as ethylene oxide in the cold. Forexample, 50 parts of glucamine may be dissolved in 50 parts of water andcooled to 20 C. 17.2 parts of ethylene oxide may then be "added. Thereaction takes place without heating. The formula of the re-. actionproduct is not definitely kno but it is believed that the reactionprobably takes place as follows:

The salts of the sugar amine bases may be prepared by melting the acidand the base together or, where either the acid or the base or both areliquids, merely by mixing.

In general, we have found'the secondary amines and their salts to bemost efiective. This is particularly true of those compounds in whicheach group is an organic group devoid of acidic substituents. Also, thesugar amines containing long chain aliphatic hydrocarbon'groups areaside as indicated above.

more soluble in the oils and fats and less soluble in water than theamines which do not contain these groups. Further, the aliphatic acidsalts, particularly those of' long chain fatty acids are generally moresoluble in the oils and fats than the free bases. By the term "longchain", as employed herein and in the claims, we mean carbon chains ofat least 8 carbon atoms.

The proportion of amine employed in any oil will depend upon theparticular oil, the particular amine and the degree of stabilizationdesired. We have found that from about 0.1% to 1.0% is satisfactory inmost cases. The amounts to be used in practice may vary from about0.001% up to 2% or more. It will generally be preferred to employamounts of not more than about 0.1% in edible fats and oils.

Some of the compounds which we have found to be particularlysatisfactory for our purpose are as follows:

methyl glucamine CH1OH(CHOH)(QHr-IL'-CH1 glucamine CH:OH(CHOH)4OH:NH:

dodecyl methyl glucamine CH;OH(CHOH)4CH:- C1|Hu H I dodecyl glucamineonlomonomlonr-i s-cunu H amyl glucamine CH:H(OHOH) OHgI IC5Hu H butylxylamine CHIOH(CII-OH)QCHI NLOQHT H methyl lructamineCH:0H(CHOH)zCH-l"I-CH:

HQOH

H methyl gelactamine CH1OH(CHOH)(CHFI-CH1 H H methyl glucamine steal-ateCH 0H(CH0H)4CH:-I i

OOCCnHu In order to more clearly ustrate our inveninto eifect, and theadvantageous results to be obtained thereby, the following examples areiven Example 1 ethylene oxide ,---a

filter paper 5" 2" were saturated with the well shaken solution and theexcess oil absorbed between clean white blotting paper. The impregnatedfilter papers were placed in carefully cleaned, glass-stoppered bottlesand stored at 65 C. in the dark, and in duplicate experiments, at roomtemperatures (25-30" C.) in diffused llght. The control or blank testswere similarly carried out on the control portion of oil set All testswere run in Days for rancidity to develop at Discoloration Agent of oil65 0. Room temp.

None (untreated oil)- 5 22 Methyl glucamine. 77 37 None. None.

. Example? To aportion of 'melted lard, 1% of methyl 7, glucamine wasadded and stirred in at about 100 C. A second portion of the same lot oflard (containing no stabilizer) was used as a blank or control. Aftercooling, rancidity tests were run with these portions of lard at 65 C.as in Example 1. The untreated lard became rancid. in two days, whereasthe treated lard required seven days to become rancid.

Example 3 A sample of cold pressed castor oil was divided into twoportions. To one was added 0.5% of methylglucamine. The other portionwas used as a blank or control. Both portions of oil were heated to 100C., as this aided in dissolving the methylglucamine in the oil to whichit was added. After cooling, filter papers were impregnated with theoils, and rancidity tests were made at 65 C. as in Example 1. Theresults are given in the following table:

Days for rancidity Discoloration Agent to develop at 65 C. oi oil None(untreat- 53 ed castor oil).

Methylgluca- 148 mine.

D efini tely yellow. None.

Note that, in this case, the inhibitor prevented the discoloration onaging that normally occurs in castor oil.

Example 4 A sample of air-blown cottonseed oil was divided into twoportions. One portion was employ'ed as a blank or c'ontrol while to theother was added 1% of methylglucamine, based on the oil. Rancidity testswere run at 65 C. as in Example 1. The untreated oil became rancid inone day. The treated oil did not become rancid in 33 days.

' Example 5 A portion of China-wood oil was heated to 420 F., requiring1 hour, held at that temperature for one hour and then cooled. To thisoil was added 0.03% of cobalt as cobalt linoleate.

' Such a composition skins over in air very badly the untreated portion.It may be noted that,

when such oil skins over, the body of the oil is protected from theatmosphere by the film or skin.

Example 6 Refined cottonseed 011 containing 1% of glucamine was testedfor rancidity at 65 0., as in Example 1 along with a portion ofuntreated cottonseed oil of the same lot. The untreated oil becamerancid in six days, whereas the treated oil required ten days to developrancidity. Neither of the oils discolored.

Example 7 Refined cottonseed oil containing 1% of ethanol glucamine wastested as in Example 1. Results:

Days for rancidity to develop Agent Discoloration 65 0. Room temperatureNone (untreated oil)- 4 8 None. Ethanolglucamine 7 15 None.

Example 8 -Refined cottonseed oil containing 1% of dodecyl methylglucamine was tested as in Example 1. The results are given in thefollowing table:

Time for rancidity to develop Discoloration Agent of on Room tem- 650perature None (untreated oil).-- 4 8 None Dodecyl methylglucamine 7 11None Example 9 Acetylated methyl glucamine was prepared by placing 312parts (3 mols) of acetic anhydrlde and 31 parts of anhydrous sodiumacetate in a reaction vessel and heating to reflux temperature. 75 partsof methylglucamine of a mole) was added in small portions. The boilingwas continued for 25 minutes, the mixture cooled, poured into 1200 partsof ice water and was then neutralized with a 40% solution of potassiumhydroxide. The precipitate, which settled out, was filtered oil andrecrystallized from 150 parts of hot water. The melting point of thematerial was 114-115 C. Analysis indicated that the formula of thematerial was one of the following:

OH: NH-CH:

l N-COCH: CH1

(CHOCO CH1): l

(CHOCOCHQA CHzOC O CH3 I (31110 COCH:

. 1% of this material was incorporated in refined cottonseed oil andtested at room temperature as in Example 1. The untreated oil developedrancidity in eight days, whereas the treated oil required twelve days todevelop this rancidity. Neither oil discolors.

Example 10 A pie crust was prepared consisting of approximately fatcontaining 1% methylglucamine. A check or control pie crust, containingthe same amount of the same fat but without a stabilizer, was alsoprepared. Each pie crust was divided into portions, one of which wascrushed and the other remained uncrushed. All

' indicate a rancid state of the lard).

Example 11 A portion of lard was treated with 0.1% methylglucamine,based on the weight of lard. Another portion of lard'was' untreated. Airwas passed through the two portions at the same rate at 100 C. The timerequired for each sample to reach a peroxide value of 20milli-equivalents of peroxide per .1000 g..of lard was determined (thisperoxide value having been previously found to It was found that 7 hourswas required for the control portion of lard to reach a peroxide valueof 20, while the time required for the lard containing 0.1%methylglucamine was 54 hours. These tests were run according to thetechnique described in Oil 8: Soap, June, 1933, p. 105-9.

Erample 12 Samples of refined cottonseed oil, containing 1%, on thebasis of the oil, of the following sugar amines, were tested forrancidity at 65 C. .as in Example 1 with results indicated below:

' Hours for rancidity Discolora- Antioxidant to develop at 65 0. tion ofoil None (untreated oil) 176 None.

Dodecyl glucamlne 382 None. Amyl glucamine-- 360 None. Butyll xylamine I528 None. Met yl fructamine.-- 494 None. Methylgalactamine- 260 None.Methyl glucamine stearate 528 None.

The above examples are merely illustrative of some of the compounds ofour invention and some of the compositions in which they may beemployed.- Our compounds may be employed to inhibit development ofrancidity in other animal 'mayonnaise, salad 'oils and the like.

and vegetable fats and oils such as linseed oil,

China-wood oil, other esters of linoleic, linolenic, and eleostearicacids, cottonseed oil, castor oil, olive oil, rape seed oil, cod liveroil and other fish oils, coconut oil, palm oil, corn oil, peanut oil,sesame oil, neatsfoot oil, butter fat, lard, beef tile lubricants, clearlacquers for coating paper,

and the like. Furthermore, the edible oils are frequently employed inthe preparation of pastries and otherbakery products, potato chips,

pounds will be found to be effective for inhibiting rancidity anddiscoloration of the oils and fats in these various tynesofcompositions.

Our compounds have been brought into intimate contact with the skinwithout having any harmful effect thereon. Small amounts of thematerialsthemselves have been eaten ,by human beings without any harmfuleffects being detected. Accordingly, it appears that our compounds areharmless or non-toxic to human beings; "They are derived from sugarswhich arev in themselves foodstufls. They do not-cause objectionabletaste or odor or discoloration of the Our comfats and oils in which theyare incorporated when employed in the proportions indicated. They havelow volatility so that they have little tendency to volatilize duringheating of the fats such as occurs during cooking or in deepfat frying 6operations. Some of them are more soluble in the fats and oils than inwater. For all of the above reasons, our compounds are particularlyadapted for use in edible fats and oils. This is an important feature ofour invention.

Other sugar amines falling within our invention are:.

Primary amines Fructamine Rhamnamine Xylamine Galactamine RibamineSorbinamine Lyxamine Sorbamine Lactamine Gulamine Arabinamine TalamineMannamine Secondary amines Ethyl glucamine Methyl xylamine Isopropylglucamine Butyl xylamlne N-butyl glucamine Benzyl xylamine Isobutylglucamine Ethyl galactamine Octyi glucamine Methyl mannamme Benzylglucumine Amyl arabinamine Cyclohexyl glucamine Diglucamine Cyclohexanolglucamine Dixylamine Phenylglucamine Difructamine 'Hydroxyplienylglucamine Reaction product of glue- Napht hyl glucamines amine andxylose Tertiary amin'es D imethyl glucamine Octyl methyl glucamineDifurfuryl glucam ne Didodecyl xylamine Dimethyl fructamine SaltsGlucamine stearate Methyl glucamine oleate Glucamine oleate Xylammestearate As has been pointed out heretofore, our amines may be employedas the free bases or as'the salts of aliphatic acids and particularly ofthe long chain or fatty acids. Among the fatty acids which may beemployed to form the salts of Eleostearic acid Abietic acid and the likeStearolic acid Some of the free amines of our invention are oil and fatsoluble and substantially insoluble in water. This is particularly trueof the sugar amines containing long chain hydrocarbon groups. Theseamines may be incorporated in the fats and oils merely by mixing. Instabilizing oils or fats in which the sugar amines are only slightlysoluble, the sugar amine to be employed should be added and well stirredinto the oil and the mixture allowed to stand until a saturated solutionis obtained when the clear oil or fat can be decanted off or filtered,or the undissolved amine can be allowed to remain in the oil or fat orcomposition containing it, as a dispersion. In some cases the sugaramines will dissolve more readily in hot oil or fat. .The least solublecangenerally be rendered soluble by employing them as their salts orsoaps, particularly, of the fatty acids.

While we have disclosed the preferred form of our invention and thepreferred modes of carrying the same. into effect, and indicated some ofthe variations and modifications that may be made 7 therein, it will bereadily apparent to those skilled in the art that many othermodifications and variations may be made therein without departing fromthe spirit of our invention. Accordingly, the scope of our invention isto be limited solely by the appended claims, construed as broadly as ispermissible in view of the prior art.

We claim:

1. Compositions comprising animal and vegetable fats and oils havingincorporated therein a sugar amine compound in which the sugar radicalcontainsat least 5 carbon atoms one carbon atom being singly bonded tothe amino nitrogen and to carbon and hydrogen solely, in an amountsuffrcient to inhibit deterioration of the fats and oils on storage.

I 2. Compositions comprising animal and vegetable fats and oils havingincorporated therein a secondary sugar amine compound in which the anamount suificient to inhibit deterioration of the fats and oils onstorage.

3. Compositions comprising animal and vegetable fats and oils havingincorporated therein a secondary sugar amine compound in which the sugarradical contains at least 5 carbon atoms one carbon atom being singlybonded to the amino nitrogen and to carbon and hydrogen solely andhaving one amino hydrogen replaced by an aliphatic group, in an amountsuflicient to inhibit deterioration of the fats and oils on storage.

4. Compositions comprising animal and vegetable fats and oils havingincorporated therein an amino alcohol compound in which the alcoholradical is an open-chain radical containing at least 5 carbon atoms onecarbon atom being singly bonded to the amino nitrogen and having ahydroxyl group attached to each carbon except the carbon attached to thenitrogen, in an amount suflicient to inhibit deterioration of the fatsand oils on storage.

5. Compositions comprising animal and vegetable fats and oils havingincorporated therein a secondary amino alcohol compound in which thealcohol radical is an open-chain radical containing at least 5 carbonatoms one carbon atom being singly bonded to the amino nitrogen andhaving a hydroxyl group attached to each carbon except the carbonattached to the nitrogen, in an amount sufdcient to inhibitdeterioration of the fats and oils on storage.

6. Compositions comprising animal and vegetable fats and oils havingincorporated therein an amino alcohol compound in which the alcoholradical is an open-chain radical containing at least 5 carbon atoms onecarbon atom being singly bonded to thgamino nitrogen and having ahydroxyl group attached to each carbon except thecarbon attached to thenitrogen and in which at least one amino hydrogen has been replaced by ahydrocarbon radical, in an amount sufficient to inhibit deterioration ofthe fats and oils on storage.

7. Compositions comprising animal and vegetable fats and oils havingincorporated therein a secondary amino alcohol compound in which thealcohol radical is an open-chain radical containing at least 5 carbonatoms one carton atom being singly bonded to the amino nitrogen andhaving a hydroxyl group attached to each carbon except the carbonattached to the nitrogen and in which the ,other substituent of thesecondary amino group is a hydrocarbon group, in an'amount.sufii cientto inhibit deterioration of the fats and oils on storage.

8. Compositions comprising animal and vegetable fats and oils havingincorporated therein an N-aliphatic substituted amino alcohol compoundin which the alcohol radical is an open-chain radical containing atleast 5 carbon atoms one carbon atom being singly bonded to the aminonitrogen and having a hydroxyl group attached to each carbon except thecarbon attached to the nitrogen, in an amount sufiicient to inhibitdeterioration of the fats and oils on storage.

9. Compositions comprising animal and vegetable fats and oils havingincorporated therein a mono N-aliphatic substituted amino alcoholcompound in which the alcohol radical is an openchain radical containingat least 5 carbon atoms one carbon atom being singly bonded to the aminonitrogen and having a hydroxyl group attached to each carbon except thecarbon attached to the nitrogen, in an amount sufiicient to inhibitdeterioration of the fats and oils on storage.

10. Compositions comprising animal and vegetable fats and oils havingincorporated therein a mono N-alkyl substituted amino alcohol compoundin which the alcohol radical is an openchain radical containing at least5 carbon atoms one carbon atom being singly bonded to the amino nitrogenand having a hydroxyl group attached to each carbon except the carbonattached to the nitrogen, in an amount sufficient to inhibitdeterioration of the fats and oils on storage.

11. Compositions comprising animal and vege-- table fats and oils havingincorporated therein an amino alcohol in which the alcohol radical is anopen-chain radical containing at least 5 carbon atoms one carbon atombeing singly bonded to the amino nitrogen and having a hydroxyl groupattached to each carbon except the carbon attached to the nitrogen, inan amount sufficient to inhibit deterioration of the fats and oils onstorage.

12. Compositions comprising animal and vegetable fats and oils havingincorporated therein a secondary amino alcohol in which the alcoholradical is an open-chain radical containing at least 5 carbon atoms onecarbon atom being singly bonded to the amino nitrogen and having ahydroxyl group attached to each carbon except the carbon attached to thenitrogen, in an amount sufiicient to inhibit deterioration of the fatsand oils on storage.

13. Compositions comprising animal and vegetable fats and oils havingincorporated therein a mono N-aliphatic substituted amino alcohol inwhich the alcohol radical is an open-chain radical containing at least 5carbon atoms one carbon atom being singly bonded to the amino nitrogenand having a hydroxyl group attached to each carbon except the carbonattached to the nitrogen, in an amount sufficient to inhibitdeterioration of the fats and oils on storage.

14. Compositions comprising animal and vegetable fats and oils havingincorporated therein a mono N-alkyl substituted amino alcohol in whichthe alcohol radical is an open-chain radical containing at least 5carbon atoms one carbon atom being singly bonded to the amino nitrogenand having a hydroxyl group attached to each a salt of an aliphatic acidand an amino alcohol in which the alcohol radical is an open-chainradical containing at least 5 carbon atoms one carbon atom being singlybonded to the amino nitrogen and having a hydroxyl group attached toeach carbon except the carbon attached to the nitrogen, in anamount=sumcient to inhibit deterioration of the rats and oils onsttfiage.

16. Compositions comprising animal and vegetable fats and oils havingincorporated therein a salt of a longchain aliphatic acid and an aminoalcohol in which the alcohol radical is an openchain radical containingat least 5 carbon atoms one carbon atom being singly bonded to the aminonitrogen'and having a hydroxyl group attached to each carbon except thecarbon attached to the nitrogen, in an amount sufflcient to inhibitdeterioration of the fats and oils on storage.

17. Compositions comprising animal and vegetable fats and oils havingincorporated therein a salt of a long chain aliphatic acid and a monoN-aliphatic substituted amino alcohol in which the alcohol radical is anopen-chain radical containing at least 5 carbon atoms one carbon atombeing singly bonded to the amino nitrogen and having a hydroxyl groupattached to each carbon except the carbon attached to the nitrogen, inan amount sumcient to inhibit deterioration of the fats and oils onstorage.

18. Compositions comprising animal and vegetable fats and oils havingincorporated therein methylglucamine in an amount sufficient to inhibitdeterioration of the fats and oils on storage.

' 19. Compositions comprising animal and vegetable fats and oils havingincorporated therein dodecylglucamine in an amount sumcient to inhibitdeterioration of the fats and oils on storage.

20. Compositions comprising animal and vegetable fats and oils havingincorporated therein Wmethylglucamine stearate in an amount suflicientto inhibit deterioration of the fats and oils on storage.

JAMES K. HUNT. GEORGE H. LATHAM.

